out.write(initial.getBytes("UTF-8"));
        }

        // Append additional content
        String append = "Appended content\n";
        try (OutputStream out = file.openOutputStream(true)) { // true = append mode
            out.write(append.getBytes("UTF-8"));
        }

        // Verify combined content
        try (InputStream in = file.getInputStream()) {

    /** Value indicating children should be merged based on element names */
    public static final String CHILDREN_COMBINATION_MERGE = "merge";
    /** Value indicating children should be appended as siblings */
    public static final String CHILDREN_COMBINATION_APPEND = "append";
    /**
     * Default mode for combining children DOMs during merge.
     * When element names match, the process will try to merge the element data,

            buf.append(".html\">File ");
            buf.append(count);
            buf.append("-");
            buf.append(i);
            buf.append("</a><br>");
            buf.append("<a href=\"dir");
            buf.append(count);
            buf.append("-");
            buf.append(i);
            buf.append("/index.html\">Dir ");
            buf.append(count);
            buf.append("-");

        @Test
        @DisplayName("Should append referral data")
        void testAppend() {
            DfsReferralDataInternal toAppend = mock(DfsReferralDataInternal.class);

            // Test with mock
            doNothing().when(mockReferralData).append(toAppend);
            mockReferralData.append(toAppend);
            verify(mockReferralData, times(1)).append(toAppend);

        StringBuilder path = new StringBuilder(128);

        path.append(formatAsDirectory(artifact.getGroupId())).append(PATH_SEPARATOR);
        path.append(artifact.getArtifactId()).append(PATH_SEPARATOR);
        path.append(artifact.getBaseVersion()).append(PATH_SEPARATOR);
        path.append(artifact.getArtifactId()).append(ARTIFACT_SEPARATOR).append(artifact.getVersion());

        if (artifact.hasClassifier()) {

                .append(ls);
        version.append("OS name: \"")
                .append(Os.OS_NAME)
                .append("\", version: \"")
                .append(Os.OS_VERSION)
                .append("\", arch: \"")
                .append(Os.OS_ARCH)
                .append("\", family: \"")
                .append(Os.OS_FAMILY)
                .append('\"');

        sb.append(dm).append(available);
        sb.append(dm).append(boost);
        sb.append(dm).append(createdBy);
        sb.append(dm).append(createdTime);
        sb.append(dm).append(description);
        sb.append(dm).append(handlerName);
        sb.append(dm).append(handlerParameter);
        sb.append(dm).append(handlerScript);
        sb.append(dm).append(name);

        sb.append(dm).append(available);
        sb.append(dm).append(crawler);
        sb.append(dm).append(createdBy);
        sb.append(dm).append(createdTime);
        sb.append(dm).append(cronExpression);
        sb.append(dm).append(jobLogging);
        sb.append(dm).append(name);
        sb.append(dm).append(scriptData);
        sb.append(dm).append(scriptType);

        sb.append(dm).append(authRealm);
        sb.append(dm).append(createdBy);
        sb.append(dm).append(createdTime);
        sb.append(dm).append(hostname);
        sb.append(dm).append(parameters);
        sb.append(dm).append(password);
        sb.append(dm).append(port);
        sb.append(dm).append(protocolScheme);
        sb.append(dm).append(updatedBy);

        sb.append(dm).append(createdBy);
        sb.append(dm).append(createdTime);
        sb.append(dm).append(fileConfigId);
        sb.append(dm).append(hostname);
        sb.append(dm).append(parameters);
        sb.append(dm).append(password);
        sb.append(dm).append(port);
        sb.append(dm).append(protocolScheme);
        sb.append(dm).append(updatedBy);